• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com
3  * Copyright (c) 2016 Facebook
4  */
5 #include <linux/kernel.h>
6 #include <linux/types.h>
7 #include <linux/slab.h>
8 #include <linux/bpf.h>
9 #include <linux/bpf_perf_event.h>
10 #include <linux/btf.h>
11 #include <linux/filter.h>
12 #include <linux/uaccess.h>
13 #include <linux/ctype.h>
14 #include <linux/kprobes.h>
15 #include <linux/spinlock.h>
16 #include <linux/syscalls.h>
17 #include <linux/error-injection.h>
18 #include <linux/btf_ids.h>
19 
20 #include <uapi/linux/bpf.h>
21 #include <uapi/linux/btf.h>
22 
23 #include <asm/tlb.h>
24 
25 #include "trace_probe.h"
26 #include "trace.h"
27 
28 #define CREATE_TRACE_POINTS
29 #include "bpf_trace.h"
30 
31 #define bpf_event_rcu_dereference(p)					\
32 	rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
33 
34 #ifdef CONFIG_MODULES
35 struct bpf_trace_module {
36 	struct module *module;
37 	struct list_head list;
38 };
39 
40 static LIST_HEAD(bpf_trace_modules);
41 static DEFINE_MUTEX(bpf_module_mutex);
42 
bpf_get_raw_tracepoint_module(const char * name)43 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
44 {
45 	struct bpf_raw_event_map *btp, *ret = NULL;
46 	struct bpf_trace_module *btm;
47 	unsigned int i;
48 
49 	mutex_lock(&bpf_module_mutex);
50 	list_for_each_entry(btm, &bpf_trace_modules, list) {
51 		for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
52 			btp = &btm->module->bpf_raw_events[i];
53 			if (!strcmp(btp->tp->name, name)) {
54 				if (try_module_get(btm->module))
55 					ret = btp;
56 				goto out;
57 			}
58 		}
59 	}
60 out:
61 	mutex_unlock(&bpf_module_mutex);
62 	return ret;
63 }
64 #else
bpf_get_raw_tracepoint_module(const char * name)65 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
66 {
67 	return NULL;
68 }
69 #endif /* CONFIG_MODULES */
70 
71 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
72 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
73 
74 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
75 				  u64 flags, const struct btf **btf,
76 				  s32 *btf_id);
77 
78 /**
79  * trace_call_bpf - invoke BPF program
80  * @call: tracepoint event
81  * @ctx: opaque context pointer
82  *
83  * kprobe handlers execute BPF programs via this helper.
84  * Can be used from static tracepoints in the future.
85  *
86  * Return: BPF programs always return an integer which is interpreted by
87  * kprobe handler as:
88  * 0 - return from kprobe (event is filtered out)
89  * 1 - store kprobe event into ring buffer
90  * Other values are reserved and currently alias to 1
91  */
trace_call_bpf(struct trace_event_call * call,void * ctx)92 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
93 {
94 	unsigned int ret;
95 
96 	cant_sleep();
97 
98 	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
99 		/*
100 		 * since some bpf program is already running on this cpu,
101 		 * don't call into another bpf program (same or different)
102 		 * and don't send kprobe event into ring-buffer,
103 		 * so return zero here
104 		 */
105 		ret = 0;
106 		goto out;
107 	}
108 
109 	/*
110 	 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
111 	 * to all call sites, we did a bpf_prog_array_valid() there to check
112 	 * whether call->prog_array is empty or not, which is
113 	 * a heurisitc to speed up execution.
114 	 *
115 	 * If bpf_prog_array_valid() fetched prog_array was
116 	 * non-NULL, we go into trace_call_bpf() and do the actual
117 	 * proper rcu_dereference() under RCU lock.
118 	 * If it turns out that prog_array is NULL then, we bail out.
119 	 * For the opposite, if the bpf_prog_array_valid() fetched pointer
120 	 * was NULL, you'll skip the prog_array with the risk of missing
121 	 * out of events when it was updated in between this and the
122 	 * rcu_dereference() which is accepted risk.
123 	 */
124 	ret = BPF_PROG_RUN_ARRAY_CHECK(call->prog_array, ctx, BPF_PROG_RUN);
125 
126  out:
127 	__this_cpu_dec(bpf_prog_active);
128 
129 	return ret;
130 }
131 
132 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
BPF_CALL_2(bpf_override_return,struct pt_regs *,regs,unsigned long,rc)133 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
134 {
135 	regs_set_return_value(regs, rc);
136 	override_function_with_return(regs);
137 	return 0;
138 }
139 
140 static const struct bpf_func_proto bpf_override_return_proto = {
141 	.func		= bpf_override_return,
142 	.gpl_only	= true,
143 	.ret_type	= RET_INTEGER,
144 	.arg1_type	= ARG_PTR_TO_CTX,
145 	.arg2_type	= ARG_ANYTHING,
146 };
147 #endif
148 
149 static __always_inline int
bpf_probe_read_user_common(void * dst,u32 size,const void __user * unsafe_ptr)150 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
151 {
152 	int ret;
153 
154 	ret = copy_from_user_nofault(dst, unsafe_ptr, size);
155 	if (unlikely(ret < 0))
156 		memset(dst, 0, size);
157 	return ret;
158 }
159 
BPF_CALL_3(bpf_probe_read_user,void *,dst,u32,size,const void __user *,unsafe_ptr)160 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
161 	   const void __user *, unsafe_ptr)
162 {
163 	return bpf_probe_read_user_common(dst, size, unsafe_ptr);
164 }
165 
166 const struct bpf_func_proto bpf_probe_read_user_proto = {
167 	.func		= bpf_probe_read_user,
168 	.gpl_only	= true,
169 	.ret_type	= RET_INTEGER,
170 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
171 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
172 	.arg3_type	= ARG_ANYTHING,
173 };
174 
175 static __always_inline int
bpf_probe_read_user_str_common(void * dst,u32 size,const void __user * unsafe_ptr)176 bpf_probe_read_user_str_common(void *dst, u32 size,
177 			       const void __user *unsafe_ptr)
178 {
179 	int ret;
180 
181 	/*
182 	 * NB: We rely on strncpy_from_user() not copying junk past the NUL
183 	 * terminator into `dst`.
184 	 *
185 	 * strncpy_from_user() does long-sized strides in the fast path. If the
186 	 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
187 	 * then there could be junk after the NUL in `dst`. If user takes `dst`
188 	 * and keys a hash map with it, then semantically identical strings can
189 	 * occupy multiple entries in the map.
190 	 */
191 	ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
192 	if (unlikely(ret < 0))
193 		memset(dst, 0, size);
194 	return ret;
195 }
196 
BPF_CALL_3(bpf_probe_read_user_str,void *,dst,u32,size,const void __user *,unsafe_ptr)197 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
198 	   const void __user *, unsafe_ptr)
199 {
200 	return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
201 }
202 
203 const struct bpf_func_proto bpf_probe_read_user_str_proto = {
204 	.func		= bpf_probe_read_user_str,
205 	.gpl_only	= true,
206 	.ret_type	= RET_INTEGER,
207 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
208 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
209 	.arg3_type	= ARG_ANYTHING,
210 };
211 
212 static __always_inline int
bpf_probe_read_kernel_common(void * dst,u32 size,const void * unsafe_ptr)213 bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr)
214 {
215 	int ret;
216 
217 	ret = copy_from_kernel_nofault(dst, unsafe_ptr, size);
218 	if (unlikely(ret < 0))
219 		memset(dst, 0, size);
220 	return ret;
221 }
222 
BPF_CALL_3(bpf_probe_read_kernel,void *,dst,u32,size,const void *,unsafe_ptr)223 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
224 	   const void *, unsafe_ptr)
225 {
226 	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
227 }
228 
229 const struct bpf_func_proto bpf_probe_read_kernel_proto = {
230 	.func		= bpf_probe_read_kernel,
231 	.gpl_only	= true,
232 	.ret_type	= RET_INTEGER,
233 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
234 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
235 	.arg3_type	= ARG_ANYTHING,
236 };
237 
238 static __always_inline int
bpf_probe_read_kernel_str_common(void * dst,u32 size,const void * unsafe_ptr)239 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
240 {
241 	int ret;
242 
243 	/*
244 	 * The strncpy_from_kernel_nofault() call will likely not fill the
245 	 * entire buffer, but that's okay in this circumstance as we're probing
246 	 * arbitrary memory anyway similar to bpf_probe_read_*() and might
247 	 * as well probe the stack. Thus, memory is explicitly cleared
248 	 * only in error case, so that improper users ignoring return
249 	 * code altogether don't copy garbage; otherwise length of string
250 	 * is returned that can be used for bpf_perf_event_output() et al.
251 	 */
252 	ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
253 	if (unlikely(ret < 0))
254 		memset(dst, 0, size);
255 	return ret;
256 }
257 
BPF_CALL_3(bpf_probe_read_kernel_str,void *,dst,u32,size,const void *,unsafe_ptr)258 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
259 	   const void *, unsafe_ptr)
260 {
261 	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
262 }
263 
264 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
265 	.func		= bpf_probe_read_kernel_str,
266 	.gpl_only	= true,
267 	.ret_type	= RET_INTEGER,
268 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
269 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
270 	.arg3_type	= ARG_ANYTHING,
271 };
272 
273 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
BPF_CALL_3(bpf_probe_read_compat,void *,dst,u32,size,const void *,unsafe_ptr)274 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
275 	   const void *, unsafe_ptr)
276 {
277 	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
278 		return bpf_probe_read_user_common(dst, size,
279 				(__force void __user *)unsafe_ptr);
280 	}
281 	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
282 }
283 
284 static const struct bpf_func_proto bpf_probe_read_compat_proto = {
285 	.func		= bpf_probe_read_compat,
286 	.gpl_only	= true,
287 	.ret_type	= RET_INTEGER,
288 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
289 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
290 	.arg3_type	= ARG_ANYTHING,
291 };
292 
BPF_CALL_3(bpf_probe_read_compat_str,void *,dst,u32,size,const void *,unsafe_ptr)293 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
294 	   const void *, unsafe_ptr)
295 {
296 	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
297 		return bpf_probe_read_user_str_common(dst, size,
298 				(__force void __user *)unsafe_ptr);
299 	}
300 	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
301 }
302 
303 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
304 	.func		= bpf_probe_read_compat_str,
305 	.gpl_only	= true,
306 	.ret_type	= RET_INTEGER,
307 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
308 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
309 	.arg3_type	= ARG_ANYTHING,
310 };
311 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
312 
BPF_CALL_3(bpf_probe_write_user,void __user *,unsafe_ptr,const void *,src,u32,size)313 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
314 	   u32, size)
315 {
316 	/*
317 	 * Ensure we're in user context which is safe for the helper to
318 	 * run. This helper has no business in a kthread.
319 	 *
320 	 * access_ok() should prevent writing to non-user memory, but in
321 	 * some situations (nommu, temporary switch, etc) access_ok() does
322 	 * not provide enough validation, hence the check on KERNEL_DS.
323 	 *
324 	 * nmi_uaccess_okay() ensures the probe is not run in an interim
325 	 * state, when the task or mm are switched. This is specifically
326 	 * required to prevent the use of temporary mm.
327 	 */
328 
329 	if (unlikely(in_interrupt() ||
330 		     current->flags & (PF_KTHREAD | PF_EXITING)))
331 		return -EPERM;
332 	if (unlikely(uaccess_kernel()))
333 		return -EPERM;
334 	if (unlikely(!nmi_uaccess_okay()))
335 		return -EPERM;
336 
337 	return copy_to_user_nofault(unsafe_ptr, src, size);
338 }
339 
340 static const struct bpf_func_proto bpf_probe_write_user_proto = {
341 	.func		= bpf_probe_write_user,
342 	.gpl_only	= true,
343 	.ret_type	= RET_INTEGER,
344 	.arg1_type	= ARG_ANYTHING,
345 	.arg2_type	= ARG_PTR_TO_MEM,
346 	.arg3_type	= ARG_CONST_SIZE,
347 };
348 
bpf_get_probe_write_proto(void)349 static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
350 {
351 	if (!capable(CAP_SYS_ADMIN))
352 		return NULL;
353 
354 	pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!",
355 			    current->comm, task_pid_nr(current));
356 
357 	return &bpf_probe_write_user_proto;
358 }
359 
bpf_trace_copy_string(char * buf,void * unsafe_ptr,char fmt_ptype,size_t bufsz)360 static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
361 		size_t bufsz)
362 {
363 	void __user *user_ptr = (__force void __user *)unsafe_ptr;
364 
365 	buf[0] = 0;
366 
367 	switch (fmt_ptype) {
368 	case 's':
369 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
370 		if ((unsigned long)unsafe_ptr < TASK_SIZE) {
371 			strncpy_from_user_nofault(buf, user_ptr, bufsz);
372 			break;
373 		}
374 		fallthrough;
375 #endif
376 	case 'k':
377 		strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz);
378 		break;
379 	case 'u':
380 		strncpy_from_user_nofault(buf, user_ptr, bufsz);
381 		break;
382 	}
383 }
384 
385 static DEFINE_RAW_SPINLOCK(trace_printk_lock);
386 
387 #define BPF_TRACE_PRINTK_SIZE   1024
388 
bpf_do_trace_printk(const char * fmt,...)389 static __printf(1, 0) int bpf_do_trace_printk(const char *fmt, ...)
390 {
391 	static char buf[BPF_TRACE_PRINTK_SIZE];
392 	unsigned long flags;
393 	va_list ap;
394 	int ret;
395 
396 	raw_spin_lock_irqsave(&trace_printk_lock, flags);
397 	va_start(ap, fmt);
398 	ret = vsnprintf(buf, sizeof(buf), fmt, ap);
399 	va_end(ap);
400 	/* vsnprintf() will not append null for zero-length strings */
401 	if (ret == 0)
402 		buf[0] = '\0';
403 	trace_bpf_trace_printk(buf);
404 	raw_spin_unlock_irqrestore(&trace_printk_lock, flags);
405 
406 	return ret;
407 }
408 
409 /*
410  * Only limited trace_printk() conversion specifiers allowed:
411  * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %pB %pks %pus %s
412  */
BPF_CALL_5(bpf_trace_printk,char *,fmt,u32,fmt_size,u64,arg1,u64,arg2,u64,arg3)413 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
414 	   u64, arg2, u64, arg3)
415 {
416 	int i, mod[3] = {}, fmt_cnt = 0;
417 	char buf[64], fmt_ptype;
418 	void *unsafe_ptr = NULL;
419 	bool str_seen = false;
420 
421 	/*
422 	 * bpf_check()->check_func_arg()->check_stack_boundary()
423 	 * guarantees that fmt points to bpf program stack,
424 	 * fmt_size bytes of it were initialized and fmt_size > 0
425 	 */
426 	if (fmt[--fmt_size] != 0)
427 		return -EINVAL;
428 
429 	/* check format string for allowed specifiers */
430 	for (i = 0; i < fmt_size; i++) {
431 		if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i]))
432 			return -EINVAL;
433 
434 		if (fmt[i] != '%')
435 			continue;
436 
437 		if (fmt_cnt >= 3)
438 			return -EINVAL;
439 
440 		/* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
441 		i++;
442 		if (fmt[i] == 'l') {
443 			mod[fmt_cnt]++;
444 			i++;
445 		} else if (fmt[i] == 'p') {
446 			mod[fmt_cnt]++;
447 			if ((fmt[i + 1] == 'k' ||
448 			     fmt[i + 1] == 'u') &&
449 			    fmt[i + 2] == 's') {
450 				fmt_ptype = fmt[i + 1];
451 				i += 2;
452 				goto fmt_str;
453 			}
454 
455 			if (fmt[i + 1] == 'B') {
456 				i++;
457 				goto fmt_next;
458 			}
459 
460 			/* disallow any further format extensions */
461 			if (fmt[i + 1] != 0 &&
462 			    !isspace(fmt[i + 1]) &&
463 			    !ispunct(fmt[i + 1]))
464 				return -EINVAL;
465 
466 			goto fmt_next;
467 		} else if (fmt[i] == 's') {
468 			mod[fmt_cnt]++;
469 			fmt_ptype = fmt[i];
470 fmt_str:
471 			if (str_seen)
472 				/* allow only one '%s' per fmt string */
473 				return -EINVAL;
474 			str_seen = true;
475 
476 			if (fmt[i + 1] != 0 &&
477 			    !isspace(fmt[i + 1]) &&
478 			    !ispunct(fmt[i + 1]))
479 				return -EINVAL;
480 
481 			switch (fmt_cnt) {
482 			case 0:
483 				unsafe_ptr = (void *)(long)arg1;
484 				arg1 = (long)buf;
485 				break;
486 			case 1:
487 				unsafe_ptr = (void *)(long)arg2;
488 				arg2 = (long)buf;
489 				break;
490 			case 2:
491 				unsafe_ptr = (void *)(long)arg3;
492 				arg3 = (long)buf;
493 				break;
494 			}
495 
496 			bpf_trace_copy_string(buf, unsafe_ptr, fmt_ptype,
497 					sizeof(buf));
498 			goto fmt_next;
499 		}
500 
501 		if (fmt[i] == 'l') {
502 			mod[fmt_cnt]++;
503 			i++;
504 		}
505 
506 		if (fmt[i] != 'i' && fmt[i] != 'd' &&
507 		    fmt[i] != 'u' && fmt[i] != 'x')
508 			return -EINVAL;
509 fmt_next:
510 		fmt_cnt++;
511 	}
512 
513 /* Horrid workaround for getting va_list handling working with different
514  * argument type combinations generically for 32 and 64 bit archs.
515  */
516 #define __BPF_TP_EMIT()	__BPF_ARG3_TP()
517 #define __BPF_TP(...)							\
518 	bpf_do_trace_printk(fmt, ##__VA_ARGS__)
519 
520 #define __BPF_ARG1_TP(...)						\
521 	((mod[0] == 2 || (mod[0] == 1 && __BITS_PER_LONG == 64))	\
522 	  ? __BPF_TP(arg1, ##__VA_ARGS__)				\
523 	  : ((mod[0] == 1 || (mod[0] == 0 && __BITS_PER_LONG == 32))	\
524 	      ? __BPF_TP((long)arg1, ##__VA_ARGS__)			\
525 	      : __BPF_TP((u32)arg1, ##__VA_ARGS__)))
526 
527 #define __BPF_ARG2_TP(...)						\
528 	((mod[1] == 2 || (mod[1] == 1 && __BITS_PER_LONG == 64))	\
529 	  ? __BPF_ARG1_TP(arg2, ##__VA_ARGS__)				\
530 	  : ((mod[1] == 1 || (mod[1] == 0 && __BITS_PER_LONG == 32))	\
531 	      ? __BPF_ARG1_TP((long)arg2, ##__VA_ARGS__)		\
532 	      : __BPF_ARG1_TP((u32)arg2, ##__VA_ARGS__)))
533 
534 #define __BPF_ARG3_TP(...)						\
535 	((mod[2] == 2 || (mod[2] == 1 && __BITS_PER_LONG == 64))	\
536 	  ? __BPF_ARG2_TP(arg3, ##__VA_ARGS__)				\
537 	  : ((mod[2] == 1 || (mod[2] == 0 && __BITS_PER_LONG == 32))	\
538 	      ? __BPF_ARG2_TP((long)arg3, ##__VA_ARGS__)		\
539 	      : __BPF_ARG2_TP((u32)arg3, ##__VA_ARGS__)))
540 
541 	return __BPF_TP_EMIT();
542 }
543 
544 static const struct bpf_func_proto bpf_trace_printk_proto = {
545 	.func		= bpf_trace_printk,
546 	.gpl_only	= true,
547 	.ret_type	= RET_INTEGER,
548 	.arg1_type	= ARG_PTR_TO_MEM,
549 	.arg2_type	= ARG_CONST_SIZE,
550 };
551 
bpf_get_trace_printk_proto(void)552 const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
553 {
554 	/*
555 	 * This program might be calling bpf_trace_printk,
556 	 * so enable the associated bpf_trace/bpf_trace_printk event.
557 	 * Repeat this each time as it is possible a user has
558 	 * disabled bpf_trace_printk events.  By loading a program
559 	 * calling bpf_trace_printk() however the user has expressed
560 	 * the intent to see such events.
561 	 */
562 	if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
563 		pr_warn_ratelimited("could not enable bpf_trace_printk events");
564 
565 	return &bpf_trace_printk_proto;
566 }
567 
568 #define MAX_SEQ_PRINTF_VARARGS		12
569 #define MAX_SEQ_PRINTF_MAX_MEMCPY	6
570 #define MAX_SEQ_PRINTF_STR_LEN		128
571 
572 struct bpf_seq_printf_buf {
573 	char buf[MAX_SEQ_PRINTF_MAX_MEMCPY][MAX_SEQ_PRINTF_STR_LEN];
574 };
575 static DEFINE_PER_CPU(struct bpf_seq_printf_buf, bpf_seq_printf_buf);
576 static DEFINE_PER_CPU(int, bpf_seq_printf_buf_used);
577 
BPF_CALL_5(bpf_seq_printf,struct seq_file *,m,char *,fmt,u32,fmt_size,const void *,data,u32,data_len)578 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
579 	   const void *, data, u32, data_len)
580 {
581 	int err = -EINVAL, fmt_cnt = 0, memcpy_cnt = 0;
582 	int i, buf_used, copy_size, num_args;
583 	u64 params[MAX_SEQ_PRINTF_VARARGS];
584 	struct bpf_seq_printf_buf *bufs;
585 	const u64 *args = data;
586 
587 	buf_used = this_cpu_inc_return(bpf_seq_printf_buf_used);
588 	if (WARN_ON_ONCE(buf_used > 1)) {
589 		err = -EBUSY;
590 		goto out;
591 	}
592 
593 	bufs = this_cpu_ptr(&bpf_seq_printf_buf);
594 
595 	/*
596 	 * bpf_check()->check_func_arg()->check_stack_boundary()
597 	 * guarantees that fmt points to bpf program stack,
598 	 * fmt_size bytes of it were initialized and fmt_size > 0
599 	 */
600 	if (fmt[--fmt_size] != 0)
601 		goto out;
602 
603 	if (data_len & 7)
604 		goto out;
605 
606 	for (i = 0; i < fmt_size; i++) {
607 		if (fmt[i] == '%') {
608 			if (fmt[i + 1] == '%')
609 				i++;
610 			else if (!data || !data_len)
611 				goto out;
612 		}
613 	}
614 
615 	num_args = data_len / 8;
616 
617 	/* check format string for allowed specifiers */
618 	for (i = 0; i < fmt_size; i++) {
619 		/* only printable ascii for now. */
620 		if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) {
621 			err = -EINVAL;
622 			goto out;
623 		}
624 
625 		if (fmt[i] != '%')
626 			continue;
627 
628 		if (fmt[i + 1] == '%') {
629 			i++;
630 			continue;
631 		}
632 
633 		if (fmt_cnt >= MAX_SEQ_PRINTF_VARARGS) {
634 			err = -E2BIG;
635 			goto out;
636 		}
637 
638 		if (fmt_cnt >= num_args) {
639 			err = -EINVAL;
640 			goto out;
641 		}
642 
643 		/* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
644 		i++;
645 
646 		/* skip optional "[0 +-][num]" width formating field */
647 		while (fmt[i] == '0' || fmt[i] == '+'  || fmt[i] == '-' ||
648 		       fmt[i] == ' ')
649 			i++;
650 		if (fmt[i] >= '1' && fmt[i] <= '9') {
651 			i++;
652 			while (fmt[i] >= '0' && fmt[i] <= '9')
653 				i++;
654 		}
655 
656 		if (fmt[i] == 's') {
657 			void *unsafe_ptr;
658 
659 			/* try our best to copy */
660 			if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
661 				err = -E2BIG;
662 				goto out;
663 			}
664 
665 			unsafe_ptr = (void *)(long)args[fmt_cnt];
666 			err = strncpy_from_kernel_nofault(bufs->buf[memcpy_cnt],
667 					unsafe_ptr, MAX_SEQ_PRINTF_STR_LEN);
668 			if (err < 0)
669 				bufs->buf[memcpy_cnt][0] = '\0';
670 			params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
671 
672 			fmt_cnt++;
673 			memcpy_cnt++;
674 			continue;
675 		}
676 
677 		if (fmt[i] == 'p') {
678 			if (fmt[i + 1] == 0 ||
679 			    fmt[i + 1] == 'K' ||
680 			    fmt[i + 1] == 'x' ||
681 			    fmt[i + 1] == 'B') {
682 				/* just kernel pointers */
683 				params[fmt_cnt] = args[fmt_cnt];
684 				fmt_cnt++;
685 				continue;
686 			}
687 
688 			/* only support "%pI4", "%pi4", "%pI6" and "%pi6". */
689 			if (fmt[i + 1] != 'i' && fmt[i + 1] != 'I') {
690 				err = -EINVAL;
691 				goto out;
692 			}
693 			if (fmt[i + 2] != '4' && fmt[i + 2] != '6') {
694 				err = -EINVAL;
695 				goto out;
696 			}
697 
698 			if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
699 				err = -E2BIG;
700 				goto out;
701 			}
702 
703 
704 			copy_size = (fmt[i + 2] == '4') ? 4 : 16;
705 
706 			err = copy_from_kernel_nofault(bufs->buf[memcpy_cnt],
707 						(void *) (long) args[fmt_cnt],
708 						copy_size);
709 			if (err < 0)
710 				memset(bufs->buf[memcpy_cnt], 0, copy_size);
711 			params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
712 
713 			i += 2;
714 			fmt_cnt++;
715 			memcpy_cnt++;
716 			continue;
717 		}
718 
719 		if (fmt[i] == 'l') {
720 			i++;
721 			if (fmt[i] == 'l')
722 				i++;
723 		}
724 
725 		if (fmt[i] != 'i' && fmt[i] != 'd' &&
726 		    fmt[i] != 'u' && fmt[i] != 'x' &&
727 		    fmt[i] != 'X') {
728 			err = -EINVAL;
729 			goto out;
730 		}
731 
732 		params[fmt_cnt] = args[fmt_cnt];
733 		fmt_cnt++;
734 	}
735 
736 	/* Maximumly we can have MAX_SEQ_PRINTF_VARARGS parameter, just give
737 	 * all of them to seq_printf().
738 	 */
739 	seq_printf(m, fmt, params[0], params[1], params[2], params[3],
740 		   params[4], params[5], params[6], params[7], params[8],
741 		   params[9], params[10], params[11]);
742 
743 	err = seq_has_overflowed(m) ? -EOVERFLOW : 0;
744 out:
745 	this_cpu_dec(bpf_seq_printf_buf_used);
746 	return err;
747 }
748 
749 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
750 
751 static const struct bpf_func_proto bpf_seq_printf_proto = {
752 	.func		= bpf_seq_printf,
753 	.gpl_only	= true,
754 	.ret_type	= RET_INTEGER,
755 	.arg1_type	= ARG_PTR_TO_BTF_ID,
756 	.arg1_btf_id	= &btf_seq_file_ids[0],
757 	.arg2_type	= ARG_PTR_TO_MEM,
758 	.arg3_type	= ARG_CONST_SIZE,
759 	.arg4_type      = ARG_PTR_TO_MEM_OR_NULL,
760 	.arg5_type      = ARG_CONST_SIZE_OR_ZERO,
761 };
762 
BPF_CALL_3(bpf_seq_write,struct seq_file *,m,const void *,data,u32,len)763 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
764 {
765 	return seq_write(m, data, len) ? -EOVERFLOW : 0;
766 }
767 
768 static const struct bpf_func_proto bpf_seq_write_proto = {
769 	.func		= bpf_seq_write,
770 	.gpl_only	= true,
771 	.ret_type	= RET_INTEGER,
772 	.arg1_type	= ARG_PTR_TO_BTF_ID,
773 	.arg1_btf_id	= &btf_seq_file_ids[0],
774 	.arg2_type	= ARG_PTR_TO_MEM,
775 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
776 };
777 
BPF_CALL_4(bpf_seq_printf_btf,struct seq_file *,m,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)778 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
779 	   u32, btf_ptr_size, u64, flags)
780 {
781 	const struct btf *btf;
782 	s32 btf_id;
783 	int ret;
784 
785 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
786 	if (ret)
787 		return ret;
788 
789 	return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
790 }
791 
792 static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
793 	.func		= bpf_seq_printf_btf,
794 	.gpl_only	= true,
795 	.ret_type	= RET_INTEGER,
796 	.arg1_type	= ARG_PTR_TO_BTF_ID,
797 	.arg1_btf_id	= &btf_seq_file_ids[0],
798 	.arg2_type	= ARG_PTR_TO_MEM,
799 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
800 	.arg4_type	= ARG_ANYTHING,
801 };
802 
803 static __always_inline int
get_map_perf_counter(struct bpf_map * map,u64 flags,u64 * value,u64 * enabled,u64 * running)804 get_map_perf_counter(struct bpf_map *map, u64 flags,
805 		     u64 *value, u64 *enabled, u64 *running)
806 {
807 	struct bpf_array *array = container_of(map, struct bpf_array, map);
808 	unsigned int cpu = smp_processor_id();
809 	u64 index = flags & BPF_F_INDEX_MASK;
810 	struct bpf_event_entry *ee;
811 
812 	if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
813 		return -EINVAL;
814 	if (index == BPF_F_CURRENT_CPU)
815 		index = cpu;
816 	if (unlikely(index >= array->map.max_entries))
817 		return -E2BIG;
818 
819 	ee = READ_ONCE(array->ptrs[index]);
820 	if (!ee)
821 		return -ENOENT;
822 
823 	return perf_event_read_local(ee->event, value, enabled, running);
824 }
825 
BPF_CALL_2(bpf_perf_event_read,struct bpf_map *,map,u64,flags)826 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
827 {
828 	u64 value = 0;
829 	int err;
830 
831 	err = get_map_perf_counter(map, flags, &value, NULL, NULL);
832 	/*
833 	 * this api is ugly since we miss [-22..-2] range of valid
834 	 * counter values, but that's uapi
835 	 */
836 	if (err)
837 		return err;
838 	return value;
839 }
840 
841 static const struct bpf_func_proto bpf_perf_event_read_proto = {
842 	.func		= bpf_perf_event_read,
843 	.gpl_only	= true,
844 	.ret_type	= RET_INTEGER,
845 	.arg1_type	= ARG_CONST_MAP_PTR,
846 	.arg2_type	= ARG_ANYTHING,
847 };
848 
BPF_CALL_4(bpf_perf_event_read_value,struct bpf_map *,map,u64,flags,struct bpf_perf_event_value *,buf,u32,size)849 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
850 	   struct bpf_perf_event_value *, buf, u32, size)
851 {
852 	int err = -EINVAL;
853 
854 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
855 		goto clear;
856 	err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
857 				   &buf->running);
858 	if (unlikely(err))
859 		goto clear;
860 	return 0;
861 clear:
862 	memset(buf, 0, size);
863 	return err;
864 }
865 
866 static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
867 	.func		= bpf_perf_event_read_value,
868 	.gpl_only	= true,
869 	.ret_type	= RET_INTEGER,
870 	.arg1_type	= ARG_CONST_MAP_PTR,
871 	.arg2_type	= ARG_ANYTHING,
872 	.arg3_type	= ARG_PTR_TO_UNINIT_MEM,
873 	.arg4_type	= ARG_CONST_SIZE,
874 };
875 
876 static __always_inline u64
__bpf_perf_event_output(struct pt_regs * regs,struct bpf_map * map,u64 flags,struct perf_sample_data * sd)877 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
878 			u64 flags, struct perf_sample_data *sd)
879 {
880 	struct bpf_array *array = container_of(map, struct bpf_array, map);
881 	unsigned int cpu = smp_processor_id();
882 	u64 index = flags & BPF_F_INDEX_MASK;
883 	struct bpf_event_entry *ee;
884 	struct perf_event *event;
885 
886 	if (index == BPF_F_CURRENT_CPU)
887 		index = cpu;
888 	if (unlikely(index >= array->map.max_entries))
889 		return -E2BIG;
890 
891 	ee = READ_ONCE(array->ptrs[index]);
892 	if (!ee)
893 		return -ENOENT;
894 
895 	event = ee->event;
896 	if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
897 		     event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
898 		return -EINVAL;
899 
900 	if (unlikely(event->oncpu != cpu))
901 		return -EOPNOTSUPP;
902 
903 	return perf_event_output(event, sd, regs);
904 }
905 
906 /*
907  * Support executing tracepoints in normal, irq, and nmi context that each call
908  * bpf_perf_event_output
909  */
910 struct bpf_trace_sample_data {
911 	struct perf_sample_data sds[3];
912 };
913 
914 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
915 static DEFINE_PER_CPU(int, bpf_trace_nest_level);
BPF_CALL_5(bpf_perf_event_output,struct pt_regs *,regs,struct bpf_map *,map,u64,flags,void *,data,u64,size)916 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
917 	   u64, flags, void *, data, u64, size)
918 {
919 	struct bpf_trace_sample_data *sds = this_cpu_ptr(&bpf_trace_sds);
920 	int nest_level = this_cpu_inc_return(bpf_trace_nest_level);
921 	struct perf_raw_record raw = {
922 		.frag = {
923 			.size = size,
924 			.data = data,
925 		},
926 	};
927 	struct perf_sample_data *sd;
928 	int err;
929 
930 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
931 		err = -EBUSY;
932 		goto out;
933 	}
934 
935 	sd = &sds->sds[nest_level - 1];
936 
937 	if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
938 		err = -EINVAL;
939 		goto out;
940 	}
941 
942 	perf_sample_data_init(sd, 0, 0);
943 	sd->raw = &raw;
944 
945 	err = __bpf_perf_event_output(regs, map, flags, sd);
946 
947 out:
948 	this_cpu_dec(bpf_trace_nest_level);
949 	return err;
950 }
951 
952 static const struct bpf_func_proto bpf_perf_event_output_proto = {
953 	.func		= bpf_perf_event_output,
954 	.gpl_only	= true,
955 	.ret_type	= RET_INTEGER,
956 	.arg1_type	= ARG_PTR_TO_CTX,
957 	.arg2_type	= ARG_CONST_MAP_PTR,
958 	.arg3_type	= ARG_ANYTHING,
959 	.arg4_type	= ARG_PTR_TO_MEM,
960 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
961 };
962 
963 static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
964 struct bpf_nested_pt_regs {
965 	struct pt_regs regs[3];
966 };
967 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
968 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
969 
bpf_event_output(struct bpf_map * map,u64 flags,void * meta,u64 meta_size,void * ctx,u64 ctx_size,bpf_ctx_copy_t ctx_copy)970 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
971 		     void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
972 {
973 	struct perf_raw_frag frag = {
974 		.copy		= ctx_copy,
975 		.size		= ctx_size,
976 		.data		= ctx,
977 	};
978 	struct perf_raw_record raw = {
979 		.frag = {
980 			{
981 				.next	= ctx_size ? &frag : NULL,
982 			},
983 			.size	= meta_size,
984 			.data	= meta,
985 		},
986 	};
987 	struct perf_sample_data *sd;
988 	struct pt_regs *regs;
989 	int nest_level;
990 	u64 ret;
991 
992 	preempt_disable();
993 	nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
994 
995 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
996 		ret = -EBUSY;
997 		goto out;
998 	}
999 	sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
1000 	regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
1001 
1002 	perf_fetch_caller_regs(regs);
1003 	perf_sample_data_init(sd, 0, 0);
1004 	sd->raw = &raw;
1005 
1006 	ret = __bpf_perf_event_output(regs, map, flags, sd);
1007 out:
1008 	this_cpu_dec(bpf_event_output_nest_level);
1009 	preempt_enable();
1010 	return ret;
1011 }
1012 
BPF_CALL_0(bpf_get_current_task)1013 BPF_CALL_0(bpf_get_current_task)
1014 {
1015 	return (long) current;
1016 }
1017 
1018 const struct bpf_func_proto bpf_get_current_task_proto = {
1019 	.func		= bpf_get_current_task,
1020 	.gpl_only	= true,
1021 	.ret_type	= RET_INTEGER,
1022 };
1023 
BPF_CALL_2(bpf_current_task_under_cgroup,struct bpf_map *,map,u32,idx)1024 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)
1025 {
1026 	struct bpf_array *array = container_of(map, struct bpf_array, map);
1027 	struct cgroup *cgrp;
1028 
1029 	if (unlikely(idx >= array->map.max_entries))
1030 		return -E2BIG;
1031 
1032 	cgrp = READ_ONCE(array->ptrs[idx]);
1033 	if (unlikely(!cgrp))
1034 		return -EAGAIN;
1035 
1036 	return task_under_cgroup_hierarchy(current, cgrp);
1037 }
1038 
1039 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {
1040 	.func           = bpf_current_task_under_cgroup,
1041 	.gpl_only       = false,
1042 	.ret_type       = RET_INTEGER,
1043 	.arg1_type      = ARG_CONST_MAP_PTR,
1044 	.arg2_type      = ARG_ANYTHING,
1045 };
1046 
1047 struct send_signal_irq_work {
1048 	struct irq_work irq_work;
1049 	struct task_struct *task;
1050 	u32 sig;
1051 	enum pid_type type;
1052 };
1053 
1054 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
1055 
do_bpf_send_signal(struct irq_work * entry)1056 static void do_bpf_send_signal(struct irq_work *entry)
1057 {
1058 	struct send_signal_irq_work *work;
1059 
1060 	work = container_of(entry, struct send_signal_irq_work, irq_work);
1061 	group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type);
1062 	put_task_struct(work->task);
1063 }
1064 
bpf_send_signal_common(u32 sig,enum pid_type type)1065 static int bpf_send_signal_common(u32 sig, enum pid_type type)
1066 {
1067 	struct send_signal_irq_work *work = NULL;
1068 
1069 	/* Similar to bpf_probe_write_user, task needs to be
1070 	 * in a sound condition and kernel memory access be
1071 	 * permitted in order to send signal to the current
1072 	 * task.
1073 	 */
1074 	if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING)))
1075 		return -EPERM;
1076 	if (unlikely(uaccess_kernel()))
1077 		return -EPERM;
1078 	if (unlikely(!nmi_uaccess_okay()))
1079 		return -EPERM;
1080 	/* Task should not be pid=1 to avoid kernel panic. */
1081 	if (unlikely(is_global_init(current)))
1082 		return -EPERM;
1083 
1084 	if (irqs_disabled()) {
1085 		/* Do an early check on signal validity. Otherwise,
1086 		 * the error is lost in deferred irq_work.
1087 		 */
1088 		if (unlikely(!valid_signal(sig)))
1089 			return -EINVAL;
1090 
1091 		work = this_cpu_ptr(&send_signal_work);
1092 		if (atomic_read(&work->irq_work.flags) & IRQ_WORK_BUSY)
1093 			return -EBUSY;
1094 
1095 		/* Add the current task, which is the target of sending signal,
1096 		 * to the irq_work. The current task may change when queued
1097 		 * irq works get executed.
1098 		 */
1099 		work->task = get_task_struct(current);
1100 		work->sig = sig;
1101 		work->type = type;
1102 		irq_work_queue(&work->irq_work);
1103 		return 0;
1104 	}
1105 
1106 	return group_send_sig_info(sig, SEND_SIG_PRIV, current, type);
1107 }
1108 
BPF_CALL_1(bpf_send_signal,u32,sig)1109 BPF_CALL_1(bpf_send_signal, u32, sig)
1110 {
1111 	return bpf_send_signal_common(sig, PIDTYPE_TGID);
1112 }
1113 
1114 static const struct bpf_func_proto bpf_send_signal_proto = {
1115 	.func		= bpf_send_signal,
1116 	.gpl_only	= false,
1117 	.ret_type	= RET_INTEGER,
1118 	.arg1_type	= ARG_ANYTHING,
1119 };
1120 
BPF_CALL_1(bpf_send_signal_thread,u32,sig)1121 BPF_CALL_1(bpf_send_signal_thread, u32, sig)
1122 {
1123 	return bpf_send_signal_common(sig, PIDTYPE_PID);
1124 }
1125 
1126 static const struct bpf_func_proto bpf_send_signal_thread_proto = {
1127 	.func		= bpf_send_signal_thread,
1128 	.gpl_only	= false,
1129 	.ret_type	= RET_INTEGER,
1130 	.arg1_type	= ARG_ANYTHING,
1131 };
1132 
BPF_CALL_3(bpf_d_path,struct path *,path,char *,buf,u32,sz)1133 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
1134 {
1135 	struct path copy;
1136 	long len;
1137 	char *p;
1138 
1139 	if (!sz)
1140 		return 0;
1141 
1142 	/*
1143 	 * The path pointer is verified as trusted and safe to use,
1144 	 * but let's double check it's valid anyway to workaround
1145 	 * potentially broken verifier.
1146 	 */
1147 	len = copy_from_kernel_nofault(&copy, path, sizeof(*path));
1148 	if (len < 0)
1149 		return len;
1150 
1151 	p = d_path(&copy, buf, sz);
1152 	if (IS_ERR(p)) {
1153 		len = PTR_ERR(p);
1154 	} else {
1155 		len = buf + sz - p;
1156 		memmove(buf, p, len);
1157 	}
1158 
1159 	return len;
1160 }
1161 
1162 BTF_SET_START(btf_allowlist_d_path)
1163 #ifdef CONFIG_SECURITY
BTF_ID(func,security_file_permission)1164 BTF_ID(func, security_file_permission)
1165 BTF_ID(func, security_inode_getattr)
1166 BTF_ID(func, security_file_open)
1167 #endif
1168 #ifdef CONFIG_SECURITY_PATH
1169 BTF_ID(func, security_path_truncate)
1170 #endif
1171 BTF_ID(func, vfs_truncate)
1172 BTF_ID(func, vfs_fallocate)
1173 BTF_ID(func, dentry_open)
1174 BTF_ID(func, vfs_getattr)
1175 BTF_ID(func, filp_close)
1176 BTF_SET_END(btf_allowlist_d_path)
1177 
1178 static bool bpf_d_path_allowed(const struct bpf_prog *prog)
1179 {
1180 	return btf_id_set_contains(&btf_allowlist_d_path, prog->aux->attach_btf_id);
1181 }
1182 
1183 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
1184 
1185 static const struct bpf_func_proto bpf_d_path_proto = {
1186 	.func		= bpf_d_path,
1187 	.gpl_only	= false,
1188 	.ret_type	= RET_INTEGER,
1189 	.arg1_type	= ARG_PTR_TO_BTF_ID,
1190 	.arg1_btf_id	= &bpf_d_path_btf_ids[0],
1191 	.arg2_type	= ARG_PTR_TO_MEM,
1192 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1193 	.allowed	= bpf_d_path_allowed,
1194 };
1195 
1196 #define BTF_F_ALL	(BTF_F_COMPACT  | BTF_F_NONAME | \
1197 			 BTF_F_PTR_RAW | BTF_F_ZERO)
1198 
bpf_btf_printf_prepare(struct btf_ptr * ptr,u32 btf_ptr_size,u64 flags,const struct btf ** btf,s32 * btf_id)1199 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
1200 				  u64 flags, const struct btf **btf,
1201 				  s32 *btf_id)
1202 {
1203 	const struct btf_type *t;
1204 
1205 	if (unlikely(flags & ~(BTF_F_ALL)))
1206 		return -EINVAL;
1207 
1208 	if (btf_ptr_size != sizeof(struct btf_ptr))
1209 		return -EINVAL;
1210 
1211 	*btf = bpf_get_btf_vmlinux();
1212 
1213 	if (IS_ERR_OR_NULL(*btf))
1214 		return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
1215 
1216 	if (ptr->type_id > 0)
1217 		*btf_id = ptr->type_id;
1218 	else
1219 		return -EINVAL;
1220 
1221 	if (*btf_id > 0)
1222 		t = btf_type_by_id(*btf, *btf_id);
1223 	if (*btf_id <= 0 || !t)
1224 		return -ENOENT;
1225 
1226 	return 0;
1227 }
1228 
BPF_CALL_5(bpf_snprintf_btf,char *,str,u32,str_size,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)1229 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
1230 	   u32, btf_ptr_size, u64, flags)
1231 {
1232 	const struct btf *btf;
1233 	s32 btf_id;
1234 	int ret;
1235 
1236 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
1237 	if (ret)
1238 		return ret;
1239 
1240 	return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
1241 				      flags);
1242 }
1243 
1244 const struct bpf_func_proto bpf_snprintf_btf_proto = {
1245 	.func		= bpf_snprintf_btf,
1246 	.gpl_only	= false,
1247 	.ret_type	= RET_INTEGER,
1248 	.arg1_type	= ARG_PTR_TO_MEM,
1249 	.arg2_type	= ARG_CONST_SIZE,
1250 	.arg3_type	= ARG_PTR_TO_MEM,
1251 	.arg4_type	= ARG_CONST_SIZE,
1252 	.arg5_type	= ARG_ANYTHING,
1253 };
1254 
1255 const struct bpf_func_proto *
bpf_tracing_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1256 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1257 {
1258 	switch (func_id) {
1259 	case BPF_FUNC_map_lookup_elem:
1260 		return &bpf_map_lookup_elem_proto;
1261 	case BPF_FUNC_map_update_elem:
1262 		return &bpf_map_update_elem_proto;
1263 	case BPF_FUNC_map_delete_elem:
1264 		return &bpf_map_delete_elem_proto;
1265 	case BPF_FUNC_map_push_elem:
1266 		return &bpf_map_push_elem_proto;
1267 	case BPF_FUNC_map_pop_elem:
1268 		return &bpf_map_pop_elem_proto;
1269 	case BPF_FUNC_map_peek_elem:
1270 		return &bpf_map_peek_elem_proto;
1271 	case BPF_FUNC_ktime_get_ns:
1272 		return &bpf_ktime_get_ns_proto;
1273 	case BPF_FUNC_ktime_get_boot_ns:
1274 		return &bpf_ktime_get_boot_ns_proto;
1275 	case BPF_FUNC_tail_call:
1276 		return &bpf_tail_call_proto;
1277 	case BPF_FUNC_get_current_pid_tgid:
1278 		return &bpf_get_current_pid_tgid_proto;
1279 	case BPF_FUNC_get_current_task:
1280 		return &bpf_get_current_task_proto;
1281 	case BPF_FUNC_get_current_uid_gid:
1282 		return &bpf_get_current_uid_gid_proto;
1283 	case BPF_FUNC_get_current_comm:
1284 		return &bpf_get_current_comm_proto;
1285 	case BPF_FUNC_trace_printk:
1286 		return bpf_get_trace_printk_proto();
1287 	case BPF_FUNC_get_smp_processor_id:
1288 		return &bpf_get_smp_processor_id_proto;
1289 	case BPF_FUNC_get_numa_node_id:
1290 		return &bpf_get_numa_node_id_proto;
1291 	case BPF_FUNC_perf_event_read:
1292 		return &bpf_perf_event_read_proto;
1293 	case BPF_FUNC_current_task_under_cgroup:
1294 		return &bpf_current_task_under_cgroup_proto;
1295 	case BPF_FUNC_get_prandom_u32:
1296 		return &bpf_get_prandom_u32_proto;
1297 	case BPF_FUNC_probe_write_user:
1298 		return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ?
1299 		       NULL : bpf_get_probe_write_proto();
1300 	case BPF_FUNC_probe_read_user:
1301 		return &bpf_probe_read_user_proto;
1302 	case BPF_FUNC_probe_read_kernel:
1303 		return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?
1304 		       NULL : &bpf_probe_read_kernel_proto;
1305 	case BPF_FUNC_probe_read_user_str:
1306 		return &bpf_probe_read_user_str_proto;
1307 	case BPF_FUNC_probe_read_kernel_str:
1308 		return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?
1309 		       NULL : &bpf_probe_read_kernel_str_proto;
1310 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1311 	case BPF_FUNC_probe_read:
1312 		return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?
1313 		       NULL : &bpf_probe_read_compat_proto;
1314 	case BPF_FUNC_probe_read_str:
1315 		return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?
1316 		       NULL : &bpf_probe_read_compat_str_proto;
1317 #endif
1318 #ifdef CONFIG_CGROUPS
1319 	case BPF_FUNC_get_current_cgroup_id:
1320 		return &bpf_get_current_cgroup_id_proto;
1321 #endif
1322 	case BPF_FUNC_send_signal:
1323 		return &bpf_send_signal_proto;
1324 	case BPF_FUNC_send_signal_thread:
1325 		return &bpf_send_signal_thread_proto;
1326 	case BPF_FUNC_perf_event_read_value:
1327 		return &bpf_perf_event_read_value_proto;
1328 	case BPF_FUNC_get_ns_current_pid_tgid:
1329 		return &bpf_get_ns_current_pid_tgid_proto;
1330 	case BPF_FUNC_ringbuf_output:
1331 		return &bpf_ringbuf_output_proto;
1332 	case BPF_FUNC_ringbuf_reserve:
1333 		return &bpf_ringbuf_reserve_proto;
1334 	case BPF_FUNC_ringbuf_submit:
1335 		return &bpf_ringbuf_submit_proto;
1336 	case BPF_FUNC_ringbuf_discard:
1337 		return &bpf_ringbuf_discard_proto;
1338 	case BPF_FUNC_ringbuf_query:
1339 		return &bpf_ringbuf_query_proto;
1340 	case BPF_FUNC_jiffies64:
1341 		return &bpf_jiffies64_proto;
1342 	case BPF_FUNC_get_task_stack:
1343 		return &bpf_get_task_stack_proto;
1344 	case BPF_FUNC_copy_from_user:
1345 		return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL;
1346 	case BPF_FUNC_snprintf_btf:
1347 		return &bpf_snprintf_btf_proto;
1348 	case BPF_FUNC_per_cpu_ptr:
1349 		return &bpf_per_cpu_ptr_proto;
1350 	case BPF_FUNC_this_cpu_ptr:
1351 		return &bpf_this_cpu_ptr_proto;
1352 	default:
1353 		return NULL;
1354 	}
1355 }
1356 
1357 static const struct bpf_func_proto *
kprobe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1358 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1359 {
1360 	switch (func_id) {
1361 	case BPF_FUNC_perf_event_output:
1362 		return &bpf_perf_event_output_proto;
1363 	case BPF_FUNC_get_stackid:
1364 		return &bpf_get_stackid_proto;
1365 	case BPF_FUNC_get_stack:
1366 		return &bpf_get_stack_proto;
1367 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
1368 	case BPF_FUNC_override_return:
1369 		return &bpf_override_return_proto;
1370 #endif
1371 	default:
1372 		return bpf_tracing_func_proto(func_id, prog);
1373 	}
1374 }
1375 
1376 /* bpf+kprobe programs can access fields of 'struct pt_regs' */
kprobe_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)1377 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1378 					const struct bpf_prog *prog,
1379 					struct bpf_insn_access_aux *info)
1380 {
1381 	if (off < 0 || off >= sizeof(struct pt_regs))
1382 		return false;
1383 	if (type != BPF_READ)
1384 		return false;
1385 	if (off % size != 0)
1386 		return false;
1387 	/*
1388 	 * Assertion for 32 bit to make sure last 8 byte access
1389 	 * (BPF_DW) to the last 4 byte member is disallowed.
1390 	 */
1391 	if (off + size > sizeof(struct pt_regs))
1392 		return false;
1393 
1394 	return true;
1395 }
1396 
1397 const struct bpf_verifier_ops kprobe_verifier_ops = {
1398 	.get_func_proto  = kprobe_prog_func_proto,
1399 	.is_valid_access = kprobe_prog_is_valid_access,
1400 };
1401 
1402 const struct bpf_prog_ops kprobe_prog_ops = {
1403 };
1404 
BPF_CALL_5(bpf_perf_event_output_tp,void *,tp_buff,struct bpf_map *,map,u64,flags,void *,data,u64,size)1405 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
1406 	   u64, flags, void *, data, u64, size)
1407 {
1408 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1409 
1410 	/*
1411 	 * r1 points to perf tracepoint buffer where first 8 bytes are hidden
1412 	 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
1413 	 * from there and call the same bpf_perf_event_output() helper inline.
1414 	 */
1415 	return ____bpf_perf_event_output(regs, map, flags, data, size);
1416 }
1417 
1418 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
1419 	.func		= bpf_perf_event_output_tp,
1420 	.gpl_only	= true,
1421 	.ret_type	= RET_INTEGER,
1422 	.arg1_type	= ARG_PTR_TO_CTX,
1423 	.arg2_type	= ARG_CONST_MAP_PTR,
1424 	.arg3_type	= ARG_ANYTHING,
1425 	.arg4_type	= ARG_PTR_TO_MEM,
1426 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1427 };
1428 
BPF_CALL_3(bpf_get_stackid_tp,void *,tp_buff,struct bpf_map *,map,u64,flags)1429 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
1430 	   u64, flags)
1431 {
1432 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1433 
1434 	/*
1435 	 * Same comment as in bpf_perf_event_output_tp(), only that this time
1436 	 * the other helper's function body cannot be inlined due to being
1437 	 * external, thus we need to call raw helper function.
1438 	 */
1439 	return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1440 			       flags, 0, 0);
1441 }
1442 
1443 static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
1444 	.func		= bpf_get_stackid_tp,
1445 	.gpl_only	= true,
1446 	.ret_type	= RET_INTEGER,
1447 	.arg1_type	= ARG_PTR_TO_CTX,
1448 	.arg2_type	= ARG_CONST_MAP_PTR,
1449 	.arg3_type	= ARG_ANYTHING,
1450 };
1451 
BPF_CALL_4(bpf_get_stack_tp,void *,tp_buff,void *,buf,u32,size,u64,flags)1452 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
1453 	   u64, flags)
1454 {
1455 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1456 
1457 	return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1458 			     (unsigned long) size, flags, 0);
1459 }
1460 
1461 static const struct bpf_func_proto bpf_get_stack_proto_tp = {
1462 	.func		= bpf_get_stack_tp,
1463 	.gpl_only	= true,
1464 	.ret_type	= RET_INTEGER,
1465 	.arg1_type	= ARG_PTR_TO_CTX,
1466 	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
1467 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1468 	.arg4_type	= ARG_ANYTHING,
1469 };
1470 
1471 static const struct bpf_func_proto *
tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1472 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1473 {
1474 	switch (func_id) {
1475 	case BPF_FUNC_perf_event_output:
1476 		return &bpf_perf_event_output_proto_tp;
1477 	case BPF_FUNC_get_stackid:
1478 		return &bpf_get_stackid_proto_tp;
1479 	case BPF_FUNC_get_stack:
1480 		return &bpf_get_stack_proto_tp;
1481 	default:
1482 		return bpf_tracing_func_proto(func_id, prog);
1483 	}
1484 }
1485 
tp_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)1486 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1487 				    const struct bpf_prog *prog,
1488 				    struct bpf_insn_access_aux *info)
1489 {
1490 	if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
1491 		return false;
1492 	if (type != BPF_READ)
1493 		return false;
1494 	if (off % size != 0)
1495 		return false;
1496 
1497 	BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
1498 	return true;
1499 }
1500 
1501 const struct bpf_verifier_ops tracepoint_verifier_ops = {
1502 	.get_func_proto  = tp_prog_func_proto,
1503 	.is_valid_access = tp_prog_is_valid_access,
1504 };
1505 
1506 const struct bpf_prog_ops tracepoint_prog_ops = {
1507 };
1508 
BPF_CALL_3(bpf_perf_prog_read_value,struct bpf_perf_event_data_kern *,ctx,struct bpf_perf_event_value *,buf,u32,size)1509 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
1510 	   struct bpf_perf_event_value *, buf, u32, size)
1511 {
1512 	int err = -EINVAL;
1513 
1514 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
1515 		goto clear;
1516 	err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
1517 				    &buf->running);
1518 	if (unlikely(err))
1519 		goto clear;
1520 	return 0;
1521 clear:
1522 	memset(buf, 0, size);
1523 	return err;
1524 }
1525 
1526 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
1527          .func           = bpf_perf_prog_read_value,
1528          .gpl_only       = true,
1529          .ret_type       = RET_INTEGER,
1530          .arg1_type      = ARG_PTR_TO_CTX,
1531          .arg2_type      = ARG_PTR_TO_UNINIT_MEM,
1532          .arg3_type      = ARG_CONST_SIZE,
1533 };
1534 
BPF_CALL_4(bpf_read_branch_records,struct bpf_perf_event_data_kern *,ctx,void *,buf,u32,size,u64,flags)1535 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
1536 	   void *, buf, u32, size, u64, flags)
1537 {
1538 	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1539 	struct perf_branch_stack *br_stack = ctx->data->br_stack;
1540 	u32 to_copy;
1541 
1542 	if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
1543 		return -EINVAL;
1544 
1545 	if (unlikely(!br_stack))
1546 		return -ENOENT;
1547 
1548 	if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
1549 		return br_stack->nr * br_entry_size;
1550 
1551 	if (!buf || (size % br_entry_size != 0))
1552 		return -EINVAL;
1553 
1554 	to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
1555 	memcpy(buf, br_stack->entries, to_copy);
1556 
1557 	return to_copy;
1558 }
1559 
1560 static const struct bpf_func_proto bpf_read_branch_records_proto = {
1561 	.func           = bpf_read_branch_records,
1562 	.gpl_only       = true,
1563 	.ret_type       = RET_INTEGER,
1564 	.arg1_type      = ARG_PTR_TO_CTX,
1565 	.arg2_type      = ARG_PTR_TO_MEM_OR_NULL,
1566 	.arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1567 	.arg4_type      = ARG_ANYTHING,
1568 };
1569 
1570 static const struct bpf_func_proto *
pe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1571 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1572 {
1573 	switch (func_id) {
1574 	case BPF_FUNC_perf_event_output:
1575 		return &bpf_perf_event_output_proto_tp;
1576 	case BPF_FUNC_get_stackid:
1577 		return &bpf_get_stackid_proto_pe;
1578 	case BPF_FUNC_get_stack:
1579 		return &bpf_get_stack_proto_pe;
1580 	case BPF_FUNC_perf_prog_read_value:
1581 		return &bpf_perf_prog_read_value_proto;
1582 	case BPF_FUNC_read_branch_records:
1583 		return &bpf_read_branch_records_proto;
1584 	default:
1585 		return bpf_tracing_func_proto(func_id, prog);
1586 	}
1587 }
1588 
1589 /*
1590  * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
1591  * to avoid potential recursive reuse issue when/if tracepoints are added
1592  * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
1593  *
1594  * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
1595  * in normal, irq, and nmi context.
1596  */
1597 struct bpf_raw_tp_regs {
1598 	struct pt_regs regs[3];
1599 };
1600 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
1601 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
get_bpf_raw_tp_regs(void)1602 static struct pt_regs *get_bpf_raw_tp_regs(void)
1603 {
1604 	struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
1605 	int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
1606 
1607 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) {
1608 		this_cpu_dec(bpf_raw_tp_nest_level);
1609 		return ERR_PTR(-EBUSY);
1610 	}
1611 
1612 	return &tp_regs->regs[nest_level - 1];
1613 }
1614 
put_bpf_raw_tp_regs(void)1615 static void put_bpf_raw_tp_regs(void)
1616 {
1617 	this_cpu_dec(bpf_raw_tp_nest_level);
1618 }
1619 
BPF_CALL_5(bpf_perf_event_output_raw_tp,struct bpf_raw_tracepoint_args *,args,struct bpf_map *,map,u64,flags,void *,data,u64,size)1620 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
1621 	   struct bpf_map *, map, u64, flags, void *, data, u64, size)
1622 {
1623 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1624 	int ret;
1625 
1626 	if (IS_ERR(regs))
1627 		return PTR_ERR(regs);
1628 
1629 	perf_fetch_caller_regs(regs);
1630 	ret = ____bpf_perf_event_output(regs, map, flags, data, size);
1631 
1632 	put_bpf_raw_tp_regs();
1633 	return ret;
1634 }
1635 
1636 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
1637 	.func		= bpf_perf_event_output_raw_tp,
1638 	.gpl_only	= true,
1639 	.ret_type	= RET_INTEGER,
1640 	.arg1_type	= ARG_PTR_TO_CTX,
1641 	.arg2_type	= ARG_CONST_MAP_PTR,
1642 	.arg3_type	= ARG_ANYTHING,
1643 	.arg4_type	= ARG_PTR_TO_MEM,
1644 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1645 };
1646 
1647 extern const struct bpf_func_proto bpf_skb_output_proto;
1648 extern const struct bpf_func_proto bpf_xdp_output_proto;
1649 
BPF_CALL_3(bpf_get_stackid_raw_tp,struct bpf_raw_tracepoint_args *,args,struct bpf_map *,map,u64,flags)1650 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
1651 	   struct bpf_map *, map, u64, flags)
1652 {
1653 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1654 	int ret;
1655 
1656 	if (IS_ERR(regs))
1657 		return PTR_ERR(regs);
1658 
1659 	perf_fetch_caller_regs(regs);
1660 	/* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
1661 	ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1662 			      flags, 0, 0);
1663 	put_bpf_raw_tp_regs();
1664 	return ret;
1665 }
1666 
1667 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
1668 	.func		= bpf_get_stackid_raw_tp,
1669 	.gpl_only	= true,
1670 	.ret_type	= RET_INTEGER,
1671 	.arg1_type	= ARG_PTR_TO_CTX,
1672 	.arg2_type	= ARG_CONST_MAP_PTR,
1673 	.arg3_type	= ARG_ANYTHING,
1674 };
1675 
BPF_CALL_4(bpf_get_stack_raw_tp,struct bpf_raw_tracepoint_args *,args,void *,buf,u32,size,u64,flags)1676 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
1677 	   void *, buf, u32, size, u64, flags)
1678 {
1679 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1680 	int ret;
1681 
1682 	if (IS_ERR(regs))
1683 		return PTR_ERR(regs);
1684 
1685 	perf_fetch_caller_regs(regs);
1686 	ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1687 			    (unsigned long) size, flags, 0);
1688 	put_bpf_raw_tp_regs();
1689 	return ret;
1690 }
1691 
1692 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
1693 	.func		= bpf_get_stack_raw_tp,
1694 	.gpl_only	= true,
1695 	.ret_type	= RET_INTEGER,
1696 	.arg1_type	= ARG_PTR_TO_CTX,
1697 	.arg2_type	= ARG_PTR_TO_MEM,
1698 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1699 	.arg4_type	= ARG_ANYTHING,
1700 };
1701 
1702 static const struct bpf_func_proto *
raw_tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1703 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1704 {
1705 	switch (func_id) {
1706 	case BPF_FUNC_perf_event_output:
1707 		return &bpf_perf_event_output_proto_raw_tp;
1708 	case BPF_FUNC_get_stackid:
1709 		return &bpf_get_stackid_proto_raw_tp;
1710 	case BPF_FUNC_get_stack:
1711 		return &bpf_get_stack_proto_raw_tp;
1712 	default:
1713 		return bpf_tracing_func_proto(func_id, prog);
1714 	}
1715 }
1716 
1717 const struct bpf_func_proto *
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1718 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1719 {
1720 	switch (func_id) {
1721 #ifdef CONFIG_NET
1722 	case BPF_FUNC_skb_output:
1723 		return &bpf_skb_output_proto;
1724 	case BPF_FUNC_xdp_output:
1725 		return &bpf_xdp_output_proto;
1726 	case BPF_FUNC_skc_to_tcp6_sock:
1727 		return &bpf_skc_to_tcp6_sock_proto;
1728 	case BPF_FUNC_skc_to_tcp_sock:
1729 		return &bpf_skc_to_tcp_sock_proto;
1730 	case BPF_FUNC_skc_to_tcp_timewait_sock:
1731 		return &bpf_skc_to_tcp_timewait_sock_proto;
1732 	case BPF_FUNC_skc_to_tcp_request_sock:
1733 		return &bpf_skc_to_tcp_request_sock_proto;
1734 	case BPF_FUNC_skc_to_udp6_sock:
1735 		return &bpf_skc_to_udp6_sock_proto;
1736 #endif
1737 	case BPF_FUNC_seq_printf:
1738 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1739 		       &bpf_seq_printf_proto :
1740 		       NULL;
1741 	case BPF_FUNC_seq_write:
1742 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1743 		       &bpf_seq_write_proto :
1744 		       NULL;
1745 	case BPF_FUNC_seq_printf_btf:
1746 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1747 		       &bpf_seq_printf_btf_proto :
1748 		       NULL;
1749 	case BPF_FUNC_d_path:
1750 		return &bpf_d_path_proto;
1751 	default:
1752 		return raw_tp_prog_func_proto(func_id, prog);
1753 	}
1754 }
1755 
raw_tp_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)1756 static bool raw_tp_prog_is_valid_access(int off, int size,
1757 					enum bpf_access_type type,
1758 					const struct bpf_prog *prog,
1759 					struct bpf_insn_access_aux *info)
1760 {
1761 	if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
1762 		return false;
1763 	if (type != BPF_READ)
1764 		return false;
1765 	if (off % size != 0)
1766 		return false;
1767 	return true;
1768 }
1769 
tracing_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)1770 static bool tracing_prog_is_valid_access(int off, int size,
1771 					 enum bpf_access_type type,
1772 					 const struct bpf_prog *prog,
1773 					 struct bpf_insn_access_aux *info)
1774 {
1775 	if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
1776 		return false;
1777 	if (type != BPF_READ)
1778 		return false;
1779 	if (off % size != 0)
1780 		return false;
1781 	return btf_ctx_access(off, size, type, prog, info);
1782 }
1783 
bpf_prog_test_run_tracing(struct bpf_prog * prog,const union bpf_attr * kattr,union bpf_attr __user * uattr)1784 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
1785 				     const union bpf_attr *kattr,
1786 				     union bpf_attr __user *uattr)
1787 {
1788 	return -ENOTSUPP;
1789 }
1790 
1791 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
1792 	.get_func_proto  = raw_tp_prog_func_proto,
1793 	.is_valid_access = raw_tp_prog_is_valid_access,
1794 };
1795 
1796 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
1797 #ifdef CONFIG_NET
1798 	.test_run = bpf_prog_test_run_raw_tp,
1799 #endif
1800 };
1801 
1802 const struct bpf_verifier_ops tracing_verifier_ops = {
1803 	.get_func_proto  = tracing_prog_func_proto,
1804 	.is_valid_access = tracing_prog_is_valid_access,
1805 };
1806 
1807 const struct bpf_prog_ops tracing_prog_ops = {
1808 	.test_run = bpf_prog_test_run_tracing,
1809 };
1810 
raw_tp_writable_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)1811 static bool raw_tp_writable_prog_is_valid_access(int off, int size,
1812 						 enum bpf_access_type type,
1813 						 const struct bpf_prog *prog,
1814 						 struct bpf_insn_access_aux *info)
1815 {
1816 	if (off == 0) {
1817 		if (size != sizeof(u64) || type != BPF_READ)
1818 			return false;
1819 		info->reg_type = PTR_TO_TP_BUFFER;
1820 	}
1821 	return raw_tp_prog_is_valid_access(off, size, type, prog, info);
1822 }
1823 
1824 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
1825 	.get_func_proto  = raw_tp_prog_func_proto,
1826 	.is_valid_access = raw_tp_writable_prog_is_valid_access,
1827 };
1828 
1829 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
1830 };
1831 
pe_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)1832 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1833 				    const struct bpf_prog *prog,
1834 				    struct bpf_insn_access_aux *info)
1835 {
1836 	const int size_u64 = sizeof(u64);
1837 
1838 	if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
1839 		return false;
1840 	if (type != BPF_READ)
1841 		return false;
1842 	if (off % size != 0) {
1843 		if (sizeof(unsigned long) != 4)
1844 			return false;
1845 		if (size != 8)
1846 			return false;
1847 		if (off % size != 4)
1848 			return false;
1849 	}
1850 
1851 	switch (off) {
1852 	case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
1853 		bpf_ctx_record_field_size(info, size_u64);
1854 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
1855 			return false;
1856 		break;
1857 	case bpf_ctx_range(struct bpf_perf_event_data, addr):
1858 		bpf_ctx_record_field_size(info, size_u64);
1859 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
1860 			return false;
1861 		break;
1862 	default:
1863 		if (size != sizeof(long))
1864 			return false;
1865 	}
1866 
1867 	return true;
1868 }
1869 
pe_prog_convert_ctx_access(enum bpf_access_type type,const struct bpf_insn * si,struct bpf_insn * insn_buf,struct bpf_prog * prog,u32 * target_size)1870 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
1871 				      const struct bpf_insn *si,
1872 				      struct bpf_insn *insn_buf,
1873 				      struct bpf_prog *prog, u32 *target_size)
1874 {
1875 	struct bpf_insn *insn = insn_buf;
1876 
1877 	switch (si->off) {
1878 	case offsetof(struct bpf_perf_event_data, sample_period):
1879 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1880 						       data), si->dst_reg, si->src_reg,
1881 				      offsetof(struct bpf_perf_event_data_kern, data));
1882 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
1883 				      bpf_target_off(struct perf_sample_data, period, 8,
1884 						     target_size));
1885 		break;
1886 	case offsetof(struct bpf_perf_event_data, addr):
1887 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1888 						       data), si->dst_reg, si->src_reg,
1889 				      offsetof(struct bpf_perf_event_data_kern, data));
1890 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
1891 				      bpf_target_off(struct perf_sample_data, addr, 8,
1892 						     target_size));
1893 		break;
1894 	default:
1895 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1896 						       regs), si->dst_reg, si->src_reg,
1897 				      offsetof(struct bpf_perf_event_data_kern, regs));
1898 		*insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
1899 				      si->off);
1900 		break;
1901 	}
1902 
1903 	return insn - insn_buf;
1904 }
1905 
1906 const struct bpf_verifier_ops perf_event_verifier_ops = {
1907 	.get_func_proto		= pe_prog_func_proto,
1908 	.is_valid_access	= pe_prog_is_valid_access,
1909 	.convert_ctx_access	= pe_prog_convert_ctx_access,
1910 };
1911 
1912 const struct bpf_prog_ops perf_event_prog_ops = {
1913 };
1914 
1915 static DEFINE_MUTEX(bpf_event_mutex);
1916 
1917 #define BPF_TRACE_MAX_PROGS 64
1918 
perf_event_attach_bpf_prog(struct perf_event * event,struct bpf_prog * prog)1919 int perf_event_attach_bpf_prog(struct perf_event *event,
1920 			       struct bpf_prog *prog)
1921 {
1922 	struct bpf_prog_array *old_array;
1923 	struct bpf_prog_array *new_array;
1924 	int ret = -EEXIST;
1925 
1926 	/*
1927 	 * Kprobe override only works if they are on the function entry,
1928 	 * and only if they are on the opt-in list.
1929 	 */
1930 	if (prog->kprobe_override &&
1931 	    (!trace_kprobe_on_func_entry(event->tp_event) ||
1932 	     !trace_kprobe_error_injectable(event->tp_event)))
1933 		return -EINVAL;
1934 
1935 	mutex_lock(&bpf_event_mutex);
1936 
1937 	if (event->prog)
1938 		goto unlock;
1939 
1940 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
1941 	if (old_array &&
1942 	    bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
1943 		ret = -E2BIG;
1944 		goto unlock;
1945 	}
1946 
1947 	ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array);
1948 	if (ret < 0)
1949 		goto unlock;
1950 
1951 	/* set the new array to event->tp_event and set event->prog */
1952 	event->prog = prog;
1953 	rcu_assign_pointer(event->tp_event->prog_array, new_array);
1954 	bpf_prog_array_free(old_array);
1955 
1956 unlock:
1957 	mutex_unlock(&bpf_event_mutex);
1958 	return ret;
1959 }
1960 
perf_event_detach_bpf_prog(struct perf_event * event)1961 void perf_event_detach_bpf_prog(struct perf_event *event)
1962 {
1963 	struct bpf_prog_array *old_array;
1964 	struct bpf_prog_array *new_array;
1965 	int ret;
1966 
1967 	mutex_lock(&bpf_event_mutex);
1968 
1969 	if (!event->prog)
1970 		goto unlock;
1971 
1972 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
1973 	ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array);
1974 	if (ret == -ENOENT)
1975 		goto unlock;
1976 	if (ret < 0) {
1977 		bpf_prog_array_delete_safe(old_array, event->prog);
1978 	} else {
1979 		rcu_assign_pointer(event->tp_event->prog_array, new_array);
1980 		bpf_prog_array_free(old_array);
1981 	}
1982 
1983 	bpf_prog_put(event->prog);
1984 	event->prog = NULL;
1985 
1986 unlock:
1987 	mutex_unlock(&bpf_event_mutex);
1988 }
1989 
perf_event_query_prog_array(struct perf_event * event,void __user * info)1990 int perf_event_query_prog_array(struct perf_event *event, void __user *info)
1991 {
1992 	struct perf_event_query_bpf __user *uquery = info;
1993 	struct perf_event_query_bpf query = {};
1994 	struct bpf_prog_array *progs;
1995 	u32 *ids, prog_cnt, ids_len;
1996 	int ret;
1997 
1998 	if (!perfmon_capable())
1999 		return -EPERM;
2000 	if (event->attr.type != PERF_TYPE_TRACEPOINT)
2001 		return -EINVAL;
2002 	if (copy_from_user(&query, uquery, sizeof(query)))
2003 		return -EFAULT;
2004 
2005 	ids_len = query.ids_len;
2006 	if (ids_len > BPF_TRACE_MAX_PROGS)
2007 		return -E2BIG;
2008 	ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
2009 	if (!ids)
2010 		return -ENOMEM;
2011 	/*
2012 	 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
2013 	 * is required when user only wants to check for uquery->prog_cnt.
2014 	 * There is no need to check for it since the case is handled
2015 	 * gracefully in bpf_prog_array_copy_info.
2016 	 */
2017 
2018 	mutex_lock(&bpf_event_mutex);
2019 	progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
2020 	ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
2021 	mutex_unlock(&bpf_event_mutex);
2022 
2023 	if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
2024 	    copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
2025 		ret = -EFAULT;
2026 
2027 	kfree(ids);
2028 	return ret;
2029 }
2030 
2031 extern struct bpf_raw_event_map __start__bpf_raw_tp[];
2032 extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
2033 
bpf_get_raw_tracepoint(const char * name)2034 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
2035 {
2036 	struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
2037 
2038 	for (; btp < __stop__bpf_raw_tp; btp++) {
2039 		if (!strcmp(btp->tp->name, name))
2040 			return btp;
2041 	}
2042 
2043 	return bpf_get_raw_tracepoint_module(name);
2044 }
2045 
bpf_put_raw_tracepoint(struct bpf_raw_event_map * btp)2046 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
2047 {
2048 	struct module *mod;
2049 
2050 	preempt_disable();
2051 	mod = __module_address((unsigned long)btp);
2052 	module_put(mod);
2053 	preempt_enable();
2054 }
2055 
2056 static __always_inline
__bpf_trace_run(struct bpf_prog * prog,u64 * args)2057 void __bpf_trace_run(struct bpf_prog *prog, u64 *args)
2058 {
2059 	cant_sleep();
2060 	rcu_read_lock();
2061 	(void) BPF_PROG_RUN(prog, args);
2062 	rcu_read_unlock();
2063 }
2064 
2065 #define UNPACK(...)			__VA_ARGS__
2066 #define REPEAT_1(FN, DL, X, ...)	FN(X)
2067 #define REPEAT_2(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
2068 #define REPEAT_3(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
2069 #define REPEAT_4(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
2070 #define REPEAT_5(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
2071 #define REPEAT_6(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
2072 #define REPEAT_7(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
2073 #define REPEAT_8(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
2074 #define REPEAT_9(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
2075 #define REPEAT_10(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
2076 #define REPEAT_11(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
2077 #define REPEAT_12(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
2078 #define REPEAT(X, FN, DL, ...)		REPEAT_##X(FN, DL, __VA_ARGS__)
2079 
2080 #define SARG(X)		u64 arg##X
2081 #define COPY(X)		args[X] = arg##X
2082 
2083 #define __DL_COM	(,)
2084 #define __DL_SEM	(;)
2085 
2086 #define __SEQ_0_11	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
2087 
2088 #define BPF_TRACE_DEFN_x(x)						\
2089 	void bpf_trace_run##x(struct bpf_prog *prog,			\
2090 			      REPEAT(x, SARG, __DL_COM, __SEQ_0_11))	\
2091 	{								\
2092 		u64 args[x];						\
2093 		REPEAT(x, COPY, __DL_SEM, __SEQ_0_11);			\
2094 		__bpf_trace_run(prog, args);				\
2095 	}								\
2096 	EXPORT_SYMBOL_GPL(bpf_trace_run##x)
2097 BPF_TRACE_DEFN_x(1);
2098 BPF_TRACE_DEFN_x(2);
2099 BPF_TRACE_DEFN_x(3);
2100 BPF_TRACE_DEFN_x(4);
2101 BPF_TRACE_DEFN_x(5);
2102 BPF_TRACE_DEFN_x(6);
2103 BPF_TRACE_DEFN_x(7);
2104 BPF_TRACE_DEFN_x(8);
2105 BPF_TRACE_DEFN_x(9);
2106 BPF_TRACE_DEFN_x(10);
2107 BPF_TRACE_DEFN_x(11);
2108 BPF_TRACE_DEFN_x(12);
2109 
__bpf_probe_register(struct bpf_raw_event_map * btp,struct bpf_prog * prog)2110 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2111 {
2112 	struct tracepoint *tp = btp->tp;
2113 
2114 	/*
2115 	 * check that program doesn't access arguments beyond what's
2116 	 * available in this tracepoint
2117 	 */
2118 	if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
2119 		return -EINVAL;
2120 
2121 	if (prog->aux->max_tp_access > btp->writable_size)
2122 		return -EINVAL;
2123 
2124 	return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func,
2125 						   prog);
2126 }
2127 
bpf_probe_register(struct bpf_raw_event_map * btp,struct bpf_prog * prog)2128 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2129 {
2130 	return __bpf_probe_register(btp, prog);
2131 }
2132 
bpf_probe_unregister(struct bpf_raw_event_map * btp,struct bpf_prog * prog)2133 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2134 {
2135 	return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog);
2136 }
2137 
bpf_get_perf_event_info(const struct perf_event * event,u32 * prog_id,u32 * fd_type,const char ** buf,u64 * probe_offset,u64 * probe_addr)2138 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
2139 			    u32 *fd_type, const char **buf,
2140 			    u64 *probe_offset, u64 *probe_addr)
2141 {
2142 	bool is_tracepoint, is_syscall_tp;
2143 	struct bpf_prog *prog;
2144 	int flags, err = 0;
2145 
2146 	prog = event->prog;
2147 	if (!prog)
2148 		return -ENOENT;
2149 
2150 	/* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
2151 	if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
2152 		return -EOPNOTSUPP;
2153 
2154 	*prog_id = prog->aux->id;
2155 	flags = event->tp_event->flags;
2156 	is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
2157 	is_syscall_tp = is_syscall_trace_event(event->tp_event);
2158 
2159 	if (is_tracepoint || is_syscall_tp) {
2160 		*buf = is_tracepoint ? event->tp_event->tp->name
2161 				     : event->tp_event->name;
2162 		*fd_type = BPF_FD_TYPE_TRACEPOINT;
2163 		*probe_offset = 0x0;
2164 		*probe_addr = 0x0;
2165 	} else {
2166 		/* kprobe/uprobe */
2167 		err = -EOPNOTSUPP;
2168 #ifdef CONFIG_KPROBE_EVENTS
2169 		if (flags & TRACE_EVENT_FL_KPROBE)
2170 			err = bpf_get_kprobe_info(event, fd_type, buf,
2171 						  probe_offset, probe_addr,
2172 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2173 #endif
2174 #ifdef CONFIG_UPROBE_EVENTS
2175 		if (flags & TRACE_EVENT_FL_UPROBE)
2176 			err = bpf_get_uprobe_info(event, fd_type, buf,
2177 						  probe_offset, probe_addr,
2178 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2179 #endif
2180 	}
2181 
2182 	return err;
2183 }
2184 
send_signal_irq_work_init(void)2185 static int __init send_signal_irq_work_init(void)
2186 {
2187 	int cpu;
2188 	struct send_signal_irq_work *work;
2189 
2190 	for_each_possible_cpu(cpu) {
2191 		work = per_cpu_ptr(&send_signal_work, cpu);
2192 		init_irq_work(&work->irq_work, do_bpf_send_signal);
2193 	}
2194 	return 0;
2195 }
2196 
2197 subsys_initcall(send_signal_irq_work_init);
2198 
2199 #ifdef CONFIG_MODULES
bpf_event_notify(struct notifier_block * nb,unsigned long op,void * module)2200 static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
2201 			    void *module)
2202 {
2203 	struct bpf_trace_module *btm, *tmp;
2204 	struct module *mod = module;
2205 	int ret = 0;
2206 
2207 	if (mod->num_bpf_raw_events == 0 ||
2208 	    (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
2209 		goto out;
2210 
2211 	mutex_lock(&bpf_module_mutex);
2212 
2213 	switch (op) {
2214 	case MODULE_STATE_COMING:
2215 		btm = kzalloc(sizeof(*btm), GFP_KERNEL);
2216 		if (btm) {
2217 			btm->module = module;
2218 			list_add(&btm->list, &bpf_trace_modules);
2219 		} else {
2220 			ret = -ENOMEM;
2221 		}
2222 		break;
2223 	case MODULE_STATE_GOING:
2224 		list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
2225 			if (btm->module == module) {
2226 				list_del(&btm->list);
2227 				kfree(btm);
2228 				break;
2229 			}
2230 		}
2231 		break;
2232 	}
2233 
2234 	mutex_unlock(&bpf_module_mutex);
2235 
2236 out:
2237 	return notifier_from_errno(ret);
2238 }
2239 
2240 static struct notifier_block bpf_module_nb = {
2241 	.notifier_call = bpf_event_notify,
2242 };
2243 
bpf_event_init(void)2244 static int __init bpf_event_init(void)
2245 {
2246 	register_module_notifier(&bpf_module_nb);
2247 	return 0;
2248 }
2249 
2250 fs_initcall(bpf_event_init);
2251 #endif /* CONFIG_MODULES */
2252